Is My Wound Infected? Use of Thermal Imaging to Assess Wound Infection

Introduction: Because the traditional signs of infection, rubor, dolor, calor, and tumor, are shared between incipient infections and aseptic inflammation, discriminating between these entities in the context of wound care represents a challenge. Objective: Here, we describe our findings on the use of infrared thermal imaging (IRT) of wounds and how this technology can be used to discriminate between inflamed and infected wounds.

Methods: A series of 4 patients with wounds suspicious of infections were imaged with a mobile IRT camera. Confirmation of an infectious process was done by microbiological culture. Analysis of the images was performed and the features that correlated with an inflammatory vs. infectious process are presented here.

Outcomes: Patient 1 presented with a post-surgical dehiscent wound following an open reduction of a tibial fracture. The IRT pattern showed an area of increased temperature in the periwound. Microbial cultures were negative, and one week later, IRT imaging showed resolution of the periwound inflammation. Patient 2 presented an ulcer secondary to a previous episode of calcaneal osteomyelitis. Infection was suspected because ulcer healing had stalled.

However, IRT imaging and bacterial cultures were negative. Patient 3 presented with a non-healing plantar ulcer. Except for discharge, the wound did not show overt signs of infection. However, IRT imaging over two subsequent weeks demonstrated a hot wound bed. Microbial cultures were positive and after a course of antibiotics, the wound started showing signs of healing. Finally, patient 4 presented with an non-healing inflamed wound. Microbial cultures were positive and IRT showed extensive hot areas in the wound bed and the periwound.

Conclusion: IRT imaging is a point-of-care technology that can potentially discriminate between aseptic inflammation and wound infection. Further studies need to be done to determine the cut-off value to diagnose the former over the latter.